Seropositivity Rate Research Articles

Gender differences in hepatitis A seropositivity rates according to the Republic of Korea's vaccination policy.

This study aimed to investigate differences in the anti-hepatitis A virus (HAV) antibody seropositivity rate by age and gender. We collected information on anti-HAV immunoglobulin G and immunoglobulin M status from samples submitted for HAV antibody testing in 2012-2022. A total of 1,333,615 cases were included in the analysis. By age, the seropositivity rate was represented by a U-shaped curve, such that the rate was low for the group aged 20 to 39 years and higher in those who were younger or older. Over time, the curve shifted rightward, and the seropositivity rate declined gradually in the group aged 35 to 39 years and older. A gender-based difference in antibody seropositivity rate was especially noticeable in the group aged 20 to 29 years. This difference between genders widened in the participants' early 20s-when men in the Republic of Korea enlist in the military-and the divergence continued subsequently for older individuals. These results indicate a higher risk of severe infection among older individuals and a gender-based difference in seroprevalence. Therefore, it is necessary to implement policies to promote vaccination in adults.

Higher correlation between neutralizing antibodies and surrogate neutralizing or binding antibodies in COVID-19 patients than vaccine recipients.

This study determined the seropositive rates and levels of antibodies to severe acute respiratory syndrome coronavirus-2 in 50 patients and 108 vaccinees using microneutralization test (MNT), surrogate virus neutralization test (sVNT), chemiluminescent microparticle immunoassay (CMIA), and electrochemiluminescence immunoassay (ECLIA). MNT, as the reference method, employed living clade S and Delta viruses to measure neutralizing (NT) antibodies, while sVNT employed wild type strain and Delta receptor-binding domains (RBD) as the test antigens to measure sVNT antibodies. CMIA and ECLIA employed only one version of RBD to measure the binding antibodies. Our study performed S gene sequencing of the test virus to exclude undesired mutants that might lead to changes in antibody levels in MNT assay. We showed that spike protein amino acid sequences of our Delta virus contained 13 amino acid changes, with 3 related to the reduced neutralization. The MNT assay showed a significant reduction in seropositive rates and antibody levels in the patients' sera when the Delta variant replaced clade S as the test virus. In contrast, the seropositive rates determined by sVNT assay using wild type strain RBD and Delta RBD were non-significantly different, suggesting that sVNT assay could not identify the difference between the antigenicity of wild type RBD and Delta RBD. Furthermore, the correlation between the levels of NT and sVNT antibodies was moderate with the patients' sera but modest with the post-vaccination sera. The seropositive rates in the patients, as determined by CMIA or ECLIA, were not different from the MNT assay using clade S, but not Delta, as the test virus. In all analyses, the correlations between the antibody levels measured by MNT and the other 3 assays were modest to moderate, with the r-values of 0.3500-0.7882.

Varicella Seroprevalence in Pediatric Populations: Results from a Single-Center Study

Objective: Varicella is a highly contagious illness with potentially severe complications, especially in young children. In Turkey, the varicella vaccine was integrated into the Universal Varicella Vaccination program in 2013, targeting 12-month-old infants. While officially reported varicella cases have decreased considerably in the past two decades, underreporting remains a challenge. This study aimed to investigate varicella seropositivity in a tertiary center. Material and Methods: A qualitative immunoassay, the enzyme-linked immunosorbent assay (ELISA), was employed to detect anti-varicella antibodies. Serum samples were collected from individuals aged 4 to 18 residing in Turkey. Information on vaccination records, varicella history, and disease notification was also collected. Results: The varicella IgG antibody records were accessed for a total of 90 children. The overall prevalence of positive varicella antibodies was 58.0% (n=47) in the study population. Seropositivity rates were 67.2% for the 4-6 age group and 30% for the 7-12 age group. Notably, the 4-6 age group showed a significant association between seropositivity and age [p=0.005; OR=4.85; 95%CI (1.614-14.569)]. Conclusion: The seropositivity rate of 58% for chickenpox is concerning. In light of this, conducting more extensive studies will provide valuable guidance. It may be worth considering the administration of an additional dose of the varicella vaccine within the age range of 4-6 years. Further research is necessary to assess the potential benefits and feasibility of implementing such a vaccination strategy.

Efficacy of COVID-19 Vaccines in Patients with Hematological Malignancy Compared to Healthy Controls: A Systematic Review and Meta-analysis.

The possibility of developing a severe coronavirus infectious (COVID-19) disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has increased, particularly in patients with hematological malignancies. These patients are more likely to produce less antibody protection due to the immunocompromised nature of the disease and the anticancer treatments. Therefore, the present systematic review intended to evaluate the seroconversion rate of COVID-19 vaccines in patients with hematological malignancies compared with healthy controls. A comprehensive systematic search was conducted in Medline via PubMed, EMBASE, and the World Health Organization COVID-19 Research Database, as well as other searches (i.e., reference list from article search and manual searches), from December 2020 to May 2022. The outcome of interest included estimating the seroconversion rates following COVID-19 vaccination in patients with hematological malignancies and comparing them with those in healthy controls. After two-step screening, the data were extracted and the summary measures were calculated using a random-effects model. A total of 39 articles regarding patients with hematological malignancies were included in the present review. After the first vaccine dose, these patients had considerably lower antibody response rates (37.0%) compared with healthy controls (74.5%). Following the second vaccine dose, the seroconversion rate in patients reached 66.8%, whereas it peaked at 97.9% in the healthy controls following complete immunization. Notably, the BNT162b2 and ChAdOx1 vaccine combination achieved the highest seropositivity rate of approximately 70%. Multiple myeloma, chronic lymphocytic leukemia, and lymphoma were the cancers of interest in most of the studies. The results of the present study highlighted the comparatively low seropositivity rates in patients with hematological malignancies, with substantial variations in rates across disease groups. The findings emphasize the possibility of additional booster doses for these individuals to enhance their immunity against SARS-CoV-2.

Helicobacter pylori exposure among the Awajún of the Peruvian Amazon: Prevalence and environmental, social, and biological associations.

Helicobacter pylori (H. pylori)-a gastric bacteria affecting almost 50% of the global population and leading to ulcers and cancer in severe cases-is a growing health concern among Indigenous populations who report a high burden of reported poor general health and gastrointestinal distress. We test hypothesized associations between H. pylori exposure patterns and environmental, social, and biological conditions among a sample of 212 Indigenous Awajún adults (112 males, 100 females, ages 18-65 years) living in the northern Peruvian Amazon. Dried blood spots were analyzed for H. pylori-specific IgG using a recently developed enzyme-linked immunosorbent assay. Resulting seropositivity rates and antibody concentrations, proxying past exposures to H. pylori were analyzed in relation to relevant environmental (toilet type, floor material, reported water quality), social (household size and education level), and biological (age, sex, BMI, blood pressure, immune and metabolic biomarkers) factors using multivariable regression analyses. We found near ubiquitous seropositivity for H. pylori exposure in our sample (99.1% seropositive). In the regression analyses, elevations in H. pylori antibody concentrations were significantly higher among males compared to females (β = 0.36, p = 0.01). No associations were found with any other factors. Anthropological research in the study communities suggests that the male bias in elevations of H. pylori antibody concentrations is related to cultural and biological factors. Future research is needed to further unravel these biocultural dynamics and determine whether elevations in H. pylori antibody concentrations have clinical relevance for gastrointestinal health outcomes in this population.

Serological Surveillance and Risk Factor Analysis for Parrot Bornavirus in Taiwan

Parrots are traded globally and pose a substantial risk for disease transmission involving parrot-specific pathogens. Parrot bornavirus (PaBV) belongs to the Bornaviridae family and encompasses two clades: alphapsittaciforme (PaBV-1 to -4, PaBV-7, and -8) and betapsittaciforme (PaBV-5 and PaBV-6). These clades cause proventricular dilatation disease, a chronic disease affecting all parrot species. PaBV infections can persist for varying durations in parrots, but the transmission routes are still not well understood. Therefore, surveillance of PaBV-infected parrots is necessary for disease control and improving psittacine aviculture. This study used isolated PaBV-4 NTUCL7 and PaBV-5 NTUCL54 strains to establish and validate two serological diagnostic methods: immunoblotting (IB) and immunocytochemical staining (ICC). To determine the prevalence of PaBV in parrots in Taiwan, 370 clinical serum samples were collected from 13 collaborative veterinary hospitals during a 1-year surveillance period. Serological surveillance revealed a seropositivity rate of 25.68%. Among the seropositive samples, 91.58% were infected with alphapsittaciforme PaBV, demonstrating the predominance of this viral clade in parrots. An analysis of risk factors also demonstrated an association between seropositivity and parrot genera, age, and clinical signs. Cohen’s kappa coefficient analysis showed a high degree of similarity (kappa value = 0.975) between the IB and ICC results, which shows that these serological diagnostic measures are robust. This study established two reliable serological diagnostic measures that are instrumental in serological surveillance, particularly in one of the major parrot-exporting regions. The surveillance results increase the understanding of PaBV infection and associated risk factors and allow methods to be devised for the conservation and protection of parrot populations.

Comparison of the effectiveness four years after Homo/Hetero prime-boost with 10 μg HP and 20 μg CHO recombinant hepatitis B vaccine at 1 and 6 months in maternal HBsAg-negative children.

Limited data were available on the effectivenessfour years after Homo or Hetero prime-boost with 10 μg Hansenulapolymorpha recombinant hepatitis B vaccine (HepB-HP) and 20 μgChinese hamster ovary cell HepB (HepB-CHO). A crosssectional study was performed in maternalhepatitis B surface antigen (HBsAg)-negative children whoreceived one dose of 10 μg HepB-HP at birth, Homo or Heteroprime-boost with 10 μg HepB-HP and 20 μg HepB-CHO at 1 and 6months. HBsAg and hepatitis B surface antibody (anti-HBs) fouryears after immunization were quantitatively detected by achemiluminescent microparticle immunoassay (CMIA). A total of 359 children were included; 119 childrenreceived two doses of 10 μg HepB-HP and 120 children receivedtwo doses of 20 μg HepB-CHO, called Homo prime-boost; 120children received Hetero prime-boost with 10 μg HepB-HP and 20μg HepB-CHO. All children were HBsAg negative. The geometricmean concentration (GMC) and overall seropositivity rate (SPR) ofanti-HBs were 59.47 (95%CI: 49.00 - 72.16) mIU/ml and 85.51%(307/359). Nearly 15% of the study subjects had an anti-HBsconcentration < 10 mIU/ml and 5.01% had an anti-HBsconcentration ≤ 2.5 mIU/ml. The GMC of the 20 μg CHO Homoprime-boost group [76.05 (95%CI: 54.97 - 105.19) mIU/ml] washigher than that of the 10 μg HP Homo group [45.86 (95%CI:31.94 - 65.84) mIU/ml] (p = 0.035). The GMCs of the Heteroprime-boost groups (10 μg HP-20 μg CHO and 20 μg CHO-10 μgHP) were 75.86 (95% CI: 48.98 - 107.15) mIU/ml and 43.65(95%CI: 27.54 - 69.18) mIU/ml, respectively (p = 0.041). Aftercontrolling for sex influence, the SPR of the 20 μg CHO Homoprime-boost group was 2.087 times than that of the 10 μg HPHomo group. The HepB booster was not necessary in the generalchildren, Homo/Hetero prime-boost with 20 μg HepB-CHO wouldincrease the anti-HBs concentration four years after immunization,timely testing and improved knowledge about the self-pay vaccinewould be good for controlling hepatitis B.

A real-world study on the changing characteristics of measles antibodies in premature infants in China

ABSTRACT The waning of maternal antibodies may cause infants to lose protection against measles before receiving measles-containing vaccine (MCV). The aim of this study is to investigate the changing characteristics and influencing factors of measles antibodies in preterm infants (PT), and to provide scientific basis for optimizing MCV vaccination strategy of the target population. Blood samples were collected from PT and full-term infants (FT) at the chronological age (CA) of 3, 6, and 12 months. Measles antibodies were quantitatively detected by enzyme-linked immunosorbent assay. Demographic and vaccination information were both collected. Kruskal–Wallis rank sum test was used to compare the measles antibodies among different gestation age (GA) groups, and multiple linear regression was performed to identify the correlative factors for the antibodies. Measles antibodies of PT decreased significantly with age increasing before MCV vaccination. The positive rates of antibodies of PT were 10.80% and 3.30% at the age of 3 and 6 months, respectively (p < .001). At 12 months, the measles antibodies and seropositive rate in the infants who received MCV vaccination increased sharply (p < .001). Regression analyzes showed that the younger the GA or the older the age, the lower the antibodies at 3 months(p < .001，p = .018); while the lower measles antibody levels at 3 months and older age predicted the lower antibodies at 6 months(p < .001, p = .029). PT were susceptible to measles due to the low level of maternally derived antibodies before MCV vaccination. More efforts should be considered to protect the vulnerable population during their early postnatal life.

Diphtheria and Tetanus Immunity Status among Greek Adults: Results from a Nationwide Seroprevalence Study.

Diphtheria and tetanus could lead to serious morbidity. We aimed to evaluate immunity levels by measuring specific IgG antibodies for diphtheria and tetanus in serum samples from a nationally expanded sample of the Greek population. A geographically stratified sampling approach based on regional units (NUTS level 2) was applied by considering variables such as age group (30-80+) and sex. In total, 1201 persons (47.7% males and 52.3% females) participated in the survey. Bivariate analysis revealed a negative relationship between diphtheria and tetanus median antibody titers and age. The overall seropositivity rate for diphtheria IgG antibodies (≥0.10 IU/mL) was estimated at 31.5%. Regarding tetanus, the total seropositivity rate was estimated at 59.5% (tetanus IgG antibodies ≥0.10 IU/mL). Logistic regression analysis indicated that age groups <40 years and 40-59 years were independently associated with tetanus seropositivity. Logistic regression also revealed that male sex and being aged 60-69 years were independent risk factors for diphtheria-related seropositivity. Lastly, being resident of some regions was an independent risk factor for both diphtheria- and tetanus-related seropositivity. The present study shows that Greek adults are still not completely immune to diphtheria and tetanus. It is likely possible to achieve optimal immunization coverage by implementing serviceable public health initiatives after comprehending real community needs.

Optimization of Mother-to-Child Hepatitis B Virus Prevention Program: Integration of Maternal Screening and Infant Post-Vaccination Serologic Testing.

Evaluation of the impact of a hepatitis B virus (HBV) prevention program that incorporates maternal antiviral prophylaxis on mother-to-child transmission (MTCT) is limited using real-world data. We analyzed data on maternal HBV screening, neonatal immunization, and post-vaccination serologic testing (PVST) for hepatitis B surface antigen (HBsAg) among at-risk infants born to HBV carrier mothers from the National Immunization Information System during 2008-2022. Through linkage with the National Health Insurance Database, information on maternal antiviral therapy was obtained. Multivariate logistic regression was performed to explore MTCT risk in relation to infant-mother characteristics and prevention strategies. In total, 2 460 218 deliveries with maternal HBV status were screened. Between 2008 and 2022, the annual HBsAg and hepatitis B e antigen (HBeAg) seropositivity rates among native pregnant women decreased from 12.2% to 2.6% and from 2.7% to 0.4%, respectively (P for both trends < .0001). Among the 22 859 at-risk infants who underwent PVST, the MTCT rates differed between infants born to HBsAg-positive/HBeAg-negative and HBeAg-positive mothers (0.75% and 6.33%, respectively; P < .001). MTCT risk increased with maternal HBeAg positivity (odds ratio [OR], 9.29; 95% confidence interval [CI], 6.79-12.73) and decreased with maternal antiviral prophylaxis (OR, 0.28; 95% CI, .16-.49). For infants with maternal HBeAg positivity, MTCT risk was associated with mothers born in the immunization era (OR, 1.40; 95% CI, 1.17-1.67). MTCT was related to maternal HBeAg positivity and effectively prevented by maternal prophylaxis in the immunized population. At-risk infants born to maternal vaccinated cohorts might possibly pose further risk.

Comprehensive landscape of neutralizing antibody and cell-mediated response elicited by the 1/5 fractional dose of 17DD-YF primary vaccination in adults

The present study aimed at evaluating the YF-specific neutralizing antibody profile besides a multiparametric analysis of phenotypic/functional features of cell-mediated response elicited by the 1/5 fractional dose of 17DD-YF vaccine, administered as a single subcutaneous injection. The immunological parameters of each volunteer was monitored at two time points, referred as: before (Day 0) [Non-Vaccinated, NV(D0)] and after vaccination (Day 30–45) [Primary Vaccinees, PV(D30–45)]. Data demonstrated high levels of neutralizing antibodies for PV(D30–45) leading to a seropositivity rate of 93%. A broad increase of systemic soluble mediators with a mixed profile was also observed for PV(D30–45), with IFN-γ and TNF-α presenting the highest baseline fold changes. Integrative network mapping of soluble mediators showed increased correlation numbers in PV(D30–45) as compared to NV(D0) (532vs398). Moreover, PV(D30–45) exhibited increased levels of Terminal Effector (CD45RA+CCR7−) CD4+ and CD8+ T-cells and Non-Classical memory B-cells (IgD+CD27+). Dimensionality reduction of Mass Cytometry data further support these findings. A polyfunctional cytokine profile (TNF-α/IFN-γ/IL-10/IL-17/IL-2) of T and B-cells was observed upon in vitro antigen recall. Mapping and kinetics timeline of soluble mediator signatures for PV(D30–45) further confirmed the polyfunctional profile upon long-term in vitro culture, mediated by increased levels of IFN-γ and TNF-α along with decreased production of IL-10. These findings suggest novel insights of correlates of protection elicited by the 1/5 fractional dose of 17DD-YF vaccine.

A Pilot Seroprevalence Study Suggests Silent Zika virus Transmission in Bhopal Region of Central India.

Several sporadic cases and outbreaks of Zika virus disease have been reported from different states of India. This paper explored the possibility of any ongoing transmission of Zika virus (ZIKV) in the Bhopal region of Central India, where the last outbreak of this disease was reported in 2018. We screened a group of 75 febrile patients who had already tested negative for the locally endemic causes of fever like dengue, chikungunya, enteric fever, malaria, and scrub typhus and two groups of asymptomatic healthy individuals represented by blood donors (n = 75) and antenatal mothers (n = 75). We tested blood samples of febrile patients for ZIKV RNA using real-time polymerase chain reaction (PCR), and for the healthy individuals, we determined anti-zika immunoglobulin G (IgG) antibodies using enzyme-linked immunosorbent assay. ZIKV RNA was not detected in any of the 75 samples tested by real-time PCR assay. Among the voluntary blood donors and antenatal mothers, a total of 10 (15.38%) and 5 (6.66%) individuals were found to be seropositive for anti-ZIKV IgG antibodies, respectively. The seropositive group was found to have higher age 33.06 (±10.83) years as compared to seronegative individuals 26.60 (±5.12) years (P = 0.037). This study, which is the first survey of seroprevalence of anti-Zika antibodies from India, reports an overall seropositivity rate of 10% for anti-Zika antibodies among the healthy population, suggesting an ongoing, low level, silent transmission of ZIKV in the local community.

Immunogenicity Assessment of the SARS-CoV-2 Protein Subunit Recombinant Vaccine (CoV2-IB 0322) in a Substudy of a Phase 3 Trial in Indonesia.

COVID-19 is one of the most devastating pandemics of the 21st century. Vaccination is one of the most effective prevention methods in combating COVID-19, and one type of vaccine being developed was the protein subunit recombinant vaccine. We evaluated the efficacy of the CoV2-IB 0322 vaccine in Depok, Indonesia. This study aimed to assess the humoral and cellular immune response of the CoV2-IB 0322 vaccine compared to an active control vaccine (COVOVAX™ Vaccine). A total of 120 subjects were enrolled and randomized into two groups, with 60 subjects in each group. Participants received either two doses of the CoV2-IB 0322 vaccine or two doses of the control vaccine with a 28-day interval between doses. Safety assessments were conducted through onsite monitoring and participant-reported adverse events. Immunogenicity was evaluated by measuring IgG anti-RBD SARS-CoV-2 and IgG-neutralizing antibodies. Cellular immunity was assessed by specific T-cell responses. Whole blood samples were collected at baseline, 14 days, 6 months, and 12 months after the second dose for cellular immunity evaluation. Both vaccines showed high seropositive rates, with neutralizing antibody and IgG titers peaking 14 days after the second dose and declining by 12 months. The seroconversion rate of anti-S IgG was 100% in both groups, but the rate of neutralizing antibody seroconversion was lower in the CoV2-IB 0322 vaccine group at 14 days after the second dose (p = 0.004). The CoV2-IB 0322 vaccine showed higher IgG GMT levels 6 and 12 months after the second dose (p < 0.001 and p = 0.01). T-cell responses, evaluated by IFN-γ, IL-2, and IL-4 production by CD4+ and CD8+ T-cells, showed similar results without significant differences between both groups, except for %IL-2/CD4+ cells 6 months after the second dose (p = 0.038). Both vaccines showed comparable B- and T-cell immunological response that diminish over time.

Incidence of canine viral diseases and prevalence of virus neutralization antibodies of canine distemper virus, adenovirus type 2, parvovirus, and parainfluenza virus type 5 in Korean dogs

Canine distemper virus (CDV), canine adenovirus type 2 (CAV-2), canine parvovirus (CPV), and canine parainfluenza virus 5 (CPIV-5) are the major viral pathogens in dogs. Despite the availability of vaccines for dogs against these four viral pathogens, investigations of antibodies against these pathogens have rarely been reported in South Korea. In this study, we investigated the recent incidence of viral diseases in dogs and conducted sero-surveillance for CDV, CAV-2, CPV, and CPIV-5 in Korean dogs. The most frequently diagnosed canine viral disease in Korean dog samples from 2000 to 2022 was CPV infection, which accounted for 48.7% (464/953) of the cases. A total of 400 dog serum samples collected between 2019 and 2022 were screened for the presence of virus-neutralizing antibodies against CDV, CAV-2, CPV, and CPIV-5. The overall seropositivity rates for CDV, CAV-2, CPV, and CPIV-5 were 83.8%, 77.8%, 99.3%, and 82.0%, respectively. The protection rate against CPV was the highest (98.3%) and that against CAV-2 was the lowest (44.8%) in dog sera. Male and female dogs showed no significant differences in seropositivity rates. CDV and CPIV-5 seropositivity increased with age in dogs, and the highest incidence and seropositivity rates of CPV indicated that Korean dogs have been continuously exposed to wild CPV, and that CPV is a pathogen that urgently requires attention among canine viral diseases.

Strongyloidiasis in Auckland: A ten-year retrospective study of diagnosis, treatment and outcomes of a predominantly Polynesian and Fijian migrant cohort.

Strongyloides stercoralis is not endemic in Aotearoa New Zealand (AoNZ). However, approximately one third of Auckland residents are born in endemic countries. This study aimed to describe the epidemiology and management of strongyloidiasis in Auckland, with a focus on migrants from Pacific Island Countries and Territories. This study retrospectively reviewed clinical, laboratory and pharmacy records data for all people diagnosed with strongyloidiasis in the Auckland region between July 2012 and June 2022. People with negative Strongyloides serology were included to estimate seropositivity rate by country of birth. Over ten years, 691 people were diagnosed with strongyloidiasis. Most diagnoses were made by serology alone (622, 90%). The median age was 63 years (range 15-92), 500 (72%) were male, and the majority were born in Polynesia (350, 51%), Fiji (130, 19%) or were of Pasifika ethnicity (an additional 7%). Twelve participants (1.7%) had severe strongyloidiasis at diagnosis. The total proportion treated with ivermectin was only 70% (484/691), with no differences between immunocompromised and immunocompetent participants, nor by ethnicity. The outcome of treatment (based on a combination of serology and/or eosinophilia and/or stool microscopy) could only be determined in 50% of the treated cohort. One participant failed treatment with ivermectin, experiencing recurrent strongyloidiasis, and another participant died in association with severe strongyloidiasis. The rate of 'positive' Strongyloides serology was highest among participants born in Samoa (48%), Fiji (39%), and Southeast Asian countries (34%). Strongyloidiasis was common and under-treated in Auckland during the study period. Clinicians should have a low threshold for considering strongyloidiasis in migrants from endemic countries, including Polynesia and Fiji.

Two-Center Comparison of Viral Hepatitis A, B, C Seroprevalence among the 18-25 Age Group

Objective: Viral hepatitis is inflammation of the liver due to a viral infection that affects millions of people worldwide, causing thousands of deaths due to acute-chronic infection, liver cancer and cirrhosis. This study is aimed to compare datas of the seroprevalence of markers for viral hepatitis A, B, C among 18-25 age group outpatient clinic patients and healthcare workers between the two University Hospitals from east and west zone of Turkey. Material and Methods: The data of a total of 562 patients and healthcare workers, aged between 18 and 25, who applied to the outpatient clinic at Sütçü İmam University Faculty of Medicine and Onsekiz Mart University Faculty of Medicine Hospital between 01.01.2022 and 01.07.2022, were retrospectively examined. The presence of serological markers against HAV, HBV, HCV and HIV was tested with the ELISA method. Results: Anti-HAV IgG positivity was 25.5% and 40.3% for Çanakkale and Kahramanmaraş, respectively. Anti-HAV seropositivity rate in Kahramanmaraş was statistically significantly higher than in Çanakkale (P&amp;lt;0.001). Anti-HBs positivity was found to be 74.5% and 75.4% for Çanakkale and Kahramanmaraş, which were similar to each other bulundu (P=0.458). HBsAg positivity was detected as 1.5% in Çanakkale and 0.8% in Kahramanmaraş. There was no significant difference between the two cities (P = 0.810). Anti-HCV was found to be positive in one (0.5%) patient in Çanakkale and in four (1.1%) patients in Kahramanmaraş. Anti-HCV positivity was higher in Kahramanmaraş and anti-HIV positivity was higher in Çanakkale (P=.03, P&amp;lt;0.001). It was detected that anti-HBs positivity (80.7%) was higher in HCWs and anti-HAV IgG positivity was higher in non-HCWs (38.4%) (P=.042, P=0.013). There was no significant difference between the 2 groups in terms of anti-HCV and anti-HIV positivity. Conclusion: Due to the low anti-HAV seropositivity rates in the 18-25 age group, this makes this group more risky in terms of HAV infection. Especially due to the anti-HAV positivity in Çanakkale is low compared to Kahramanmaraş, it is recommended to support vaccination in this region. Since health care workers are at risk of having and transmitting hepatitis, it was found to be appropriate getting prevention measures by screening against vaccine-preventable diseases.

A Retrospective Analysis of Systemic Bartonella henselae Infection in Children.

Systemic Bartonella henselae infection, also known as cat-scratch disease (CSD), presents a diagnostic challenge due to the variability of clinical manifestations and the potential for serological cross-reactivity with other organisms. This study aimed to retrospectively analyze the epidemiological, clinical, laboratory, and imaging characteristics of pediatric patients diagnosed with systemic B. henselae infection, to improve understanding and facilitate timely diagnosis and treatment. We conducted a 10-year retrospective study at the "Louis Turcanu" Children's Emergency Hospital and private clinics in Timisoara, Romania, reviewing records for confirmed cases of B. henselae infection from January 2014 to January 2024. The study adhered to the Declaration of Helsinki and received approval from the Institutional Review Board. Diagnostic criteria included contact with animals, prolonged fever, hematological and/or hepatosplenic manifestations, and positive serological tests for B. henselae. Nineteen pediatric patients were identified with a median age of 8.1 years. The majority were exposed to felines (94.7%), reflecting the disease's epidemiological profile. Clinical findings highlighted fever (47.4%), lymphadenopathy (78.9%), and less frequently, abdominal pain and headache (both 10.5%). Laboratory analyses revealed a mean hemoglobin of 12.6 mg/dL, WBC count of 13.1 × 103 cells/microliter, and platelet count of 340.6 × 103 per microliter. Significant findings included elevation in ESR and CRP in 47.4% and 21.1% of patients, respectively, and high seropositivity rates for B. henselae IgM (63.2%) and IgG (94.7%). Imaging studies demonstrated widespread lymphadenopathy and occasional splenomegaly and hepatic microabscesses. All patients received antibiotic therapy, with azithromycin being the most commonly used (94.7%). Co-infections with Epstein-Barr Virus, Cytomegalovirus, and Toxoplasma gondii were documented, indicating the complex infectious status of the patients. Systemic B. henselae infection in children predominantly manifests with fever and lymphadenopathy, with a significant history of exposure to felines. Laboratory and imaging findings support the diagnosis, which is further complicated by potential co-infections. Effective antibiotic therapy, primarily with azithromycin, underscores the need for comprehensive diagnostic and treatment strategies. This study emphasizes the importance of considering systemic B. henselae infection in pediatric patients with prolonged fever and contact with cats, to ensure timely and appropriate treatment.

Immunogenicity and Safety of Half-Dose Heterologous mRNA-1273 Booster Vaccination for Adults Primed with the CoronaVac® and ChAdOx1-S Vaccines for SARS-CoV-2.

Coronavirus disease 2019 (COVID-19) has been extensively researched, particularly with regard to COVID-19 vaccines. However, issues with logistics and availability might cause delays in vaccination programs. Thus, the efficacy and safety of half-dose heterologous mRNA should be explored. This was an open-label observational study to evaluate the immunogenicity and safety of half-dose mRNA-1273 as a booster vaccine among adults aged >18 years who underwent a complete primary SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) vaccination regimen with CoronaVac® and ChAdOx1-S. Adverse events (AEs), seropositivity rate, seroconversion, geometric mean titer (GMT) of SARS-CoV-2 antibodies, neutralizing antibodies, and T cells (CD4+ and CD8+) specific for SARS-CoV-2 were analyzed. Two hundred subjects were included in the final analysis, with 100 subjects in each priming vaccine group. Most of the AEs were mild, with systemic manifestations occurring between 1 and 7 days following vaccination. A significant difference was observed in the GMT and seropositivity rate following booster dose administration between the two groups. CD8+/CD3+, IFN (interferon)-producing CD8+, and TNF (tumor necrosis factor)-producing CD8+ cells showed significant increases in both groups. The administration of the half-dose mRNA-1273 booster is safe and effective in increasing protection against SARS-CoV-2 infection.

The seroepidemiology of immunoglobulin G antibodies against pertussis toxin and filamentous hemagglutinin in the east of China during the COVID-19 pandemic.

This study employed sero-epidemiological methods to estimate the incidence of pertussis within a healthy population located in eastern China. The aim was to gain deeper insights into the epidemiological characteristics and burden of pertussis within the country. Blood samples were collected from healthy individuals in Jiangsu Province between June 2019 and December 2022. The levels of IgG antibodies against pertussis toxin (anti-PT) and filamentous hemagglutinin (anti-FHA) in the serum were quantitatively measured using enzyme-linked immunosorbent assay (ELISA). Additionally, pertussis case data reported in Jiangsu Province were collected from the China Information System for Disease Control and Prevention and compared with the results of this study. In 2022, the reported incidence of pertussis stood at 1.0 per 100,000 individuals, marking the highest rate observed in the past two decades. Among 1,909 patients examined, the geometric mean concentration (GMC) of anti-PT IgG antibody was 20.2 (18.5-21.9) IU/ml, while that of anti-FHA IgG antibody was 27.0 (25.4-28.7) IU/ml. The IgG-PT and IgG-FHA seropositivity rate (>20.0 IU/ml) was highest in the 1 ~ 2 y old group and decreased rapidly to the lowest in the 3 ~ 4 y old group and then increased gradually with age. The estimated rate of pertussis infection based on seroprevalence was approximately 25,625-fold higher than the reported notification rate in the ≥15 year age group. Our findings highlight decreased immunity post-vaccination, stressing the importance of additional booster shots for adolescents and adults to maintain immunity and reduce severe illness. Additionally, they offer vital guidance for policymakers to enhance immunization strategies.

Serostatus of Coxsackie B in a sample of women with miscarriage in Baghdad, Iraq.

The antibody that crosses transplacentally from mother to fetus is very important origin of protective passive immunity against infection neonatal with enterovirus. Important varieties of coxsackievirus B3 (CVB3) are responsible for infections in newborns. The purpose from this study is to investigate in the prevalence of Coxsackie B virus in a sample of Iraqi women with miscarriage and potential role of miscarriage risk. Between November 2022 and June 2023, we included 91parturient women (gestational age: 4-20weeks) who were between the ages of 15 and 40. Every participant completed a questionnaire, and blood was drawn to assess maternal antibodies against CVB3. The blood seropositive rates were 46 out 91(50.54%), 2 out 46 were IgM positive (4.34%), (8-12weeks) 23 from 46 (50%) (p-value 0.0294) gestational age more frequent among aborted women that positive for anti-coxsackie B antibody, The 25-35age group was significantly overrepresented (51/91, 56%) compared to other age groups. This investigation posits Coxsackie B virus (CBV) as a possible etiology for miscarriage in the Iraqi female population. Further studies employing larger cohorts and robust methodologies, beyond the current detection technique, are warranted to corroborate these observations and elucidate the potential mechanisms by which CBV might induce miscarriage.